Grade 7 Unit A Notes Interactions and Ecosystems

Relationships exist between living things and their environment. Examples?

1.1 Defining an Ecosystem and Learning about Basic Needs An ecosystem is an area where living things interact with other living things and non-living things. Biotic Factors – living things within an ecosystem. [bio = life] Abiotic Factors – non-living things in an ecosystem.

Example : Your Backyard Biotic Abiotic Plants Soil Insects Water Animals Air

Ecosystems may be as large as an ocean or desert or as small as a puddle or rotting log. Earth contains many ecosystems. Each ecosystem contains a variety of different species.

Species – living things that can reproduce young that resemble their parents. Population – a number of members of the same species living together in the same area. Edmonton Population:1,040,000 Canada Population: 33,390,141 World Population: 6,602,224,175

Community– all the populations of different species living and interacting in the same area. Ecosystem – an area where all living things and non-living things within a community interact.

The needs of living things within an ecosystem include: Water Food to provide nutrients (carbohydrates, fats, proteins, vitamins, & minerals) Energy to sustain activity Oxygen for cellular respiration Suitable living conditions (eg. Range of temperature and shelter) Cellular Respiration – the breaking down of food for cells.

1.2 Interactions among Living Things

Symbiotic Relationships Symbiosis – is whenever different living things live closely together where the relationship may benefit one or both living things unlike a predator/prey relationship, a symbiotic relationship rarely ends in the death of one or the two organisms.

Example

Types of symbiotic relationships include: Commensalism – is when one of the species in the relationship benefits while the other one neither benefits nor is harmed. Example: barnacles growing on a whale

Mutualism – is when both species in the relationship benefit Example: a snapping shrimp and a goby fish

These red-billed oxpeckers enjoy a symbiotic relationship with an impala in the African savanna

Parasitism – is when one of the species in the relationship benefits while the other is harmed but not typically to the point of death. Examples: you and a mosquito, or a dog and fleas

All of these relationships involve a behavioral adaptation Adaptation - in general, are ways in which an organism responds to its environment. Example of a physical adaptation: The bills and legs of the Great Blue Heron allow them to fish in shallow water.

Successful adaptations typically allow a parent to survive and pass on the characteristics to the next generation.

Nice view…..

Improvements over the years: 1. Recycling – management of items such as paper, glass, plastics, etc…

2. Composting – management of biodegradable waste.

3. Incinerating – burning of waste products where toxic fumes are not likely.

4. Hazardous waste operations – management of waste poisonous to the environment.

5. Sanitary Landfills – open pits that are lined with clay and a system of pipes to prevent leaking and compacted in 0.5m layers.